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Search results for: COSY
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Absolute configurations of C34 and C35 of antibiotic niphimycin A
PublicationThe relative configurations of four stereogenic centers of the C33-C42 fragment of niphimycin A were assigned as 2S*, 3R*, 4S* and 6S*, based upon (1)H NMR analysis with double-quantum filtered COSY and nuclear Overhauser spectroscopy experiments. These data were then correlated with absolute configurations at C36 and C38 of niphimycin A, which were declared previously as 36S and 38S [3]. This allowed for the assignment of the...
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Stereostructure of mycoheptin A2
PublicationThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previouslyelaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. Thestructure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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Stereostructure of mycoheptin A2
PublicationThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previously elaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. The structure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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The stereostructure of candicidin D.
PublicationThe candicidin D stereostructure was established based on NMR studies including DQF-COSY, ROESY, HSQC and HMBC experiments. The relative configurations of the candicidin D stereogenic centers were assigned as the following: 9R*, 11S*, 13S*, 15R*, 17S*, 18R*, 19S*, 21R*, 36S*, 37R*, 38S*, 40S* and 41S*. The geometry of the heptaene chromophore was defined as 22E, 24E, 26Z, 28Z, 30E, 32E and 34E.
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Absolute configurations of C34 and C35 of antibiotic niphimycin A
PublicationThe relative configurations of four stereogenic centers of the C33-C42 fragment of niphimycin A were assigned as 2S*, 3R*, 4S* and 6S*, based upon 1H NMR analysis with double-quantum filtered COSY and nuclear Overhauser spectroscopy experiments. These data were then correlated with absolute configurations at C36 and C38 of niphimycin A, which were declared previously as 36S and 38S [3]. This allowed for the assignment of the absolute...
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Monosaccharides as internal probes for the determination of the absolute configuration of 2-butanol
PublicationD-dlukoza, D-mannoza i L-ramnoza zostały poddane reakcji z mieszaniną racemiczną 2-butanolu. Otrzymane w ten sposób glikozydy były analizowane za pomocą spektroskopii NMR, z wykorzystaniem eksperymentów COSY i NOESY. Analiza konformacyjna wiązania glikozydowego (dokonana w oparciu o modelowanie molekularne i heteronuklearne stałe sprzężenia) wraz z analizą sprzężeń dipolowych obserwowanych w widmie NOESY umożliwiła określenie konfiguracji...
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Synthesis and structure determination of 2,3-diaryl-9,9-dioxo-1H-9-thia-1,4,4a,7,10-pentaazaphenanthrene-2-ols
Publication3-Amino-1,1-dioxopyrido[4,3-e]-1,4,2-dithiazine has been synthesized and applied to the synthesis of 3-amino-2-(4-thioxo-1,4-dihydropyridin-3-ylsulfonyl)guanidine. The reaction of the aminoguanidine with the appropriate 1,2-diarylethane-1,2-diones afforded 2,3-diaryl-9,9-dioxo-1H-9-thia-1,4,4a,7,10-pentaazaphenanthrene-2-ol derivatives. The structure of these compounds, which represent a novel heterocyclic ring system, was confirmed...
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Light-Induced Transformation of the Aromatic Heptaene Antifungal Antibiotic Candicidin D into Its All-Trans Isomer
PublicationIllumination of the aromatic heptaene macrolide antifungal antibiotic candicicin D with UV light results in an isomerization of the molecule. The product formed after irradiation of the candicidin complex with UV light (λ=365nm), namely, iso-candicidin D, was isolated and subjected to 2D NMR studies, consisting of DQF-COSY, ROESY, TOCSY, HSQC, and HMBC experiments. The obtained spectral data unambiguously evidenced that iso-candicidin...
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The complete stereochemistry of the antibiotic candicidin A3 (syn. ascosin A3, levorin A3)
PublicationHerein, the stereostructure of the aromatic heptaene macrolide (AHM) antifungal antibiotic candicidin A3 (syn. ascosin A3, levorin A3) has been established upon the 2D NMR studies, consisting of DQF-COSY, TOCSY, ROESY, HSQC and HMBC experiments, as well as upon extensive molecular dynamics simulations. The geometry of the heptaenic chromophore was defined as: (22E, 24E, 26Z, 28Z, 30E, 32E, 34E). The previously unreported absolute...
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The structure of nystatin A2
PublicationBudowa chemiczna składnika kompleksu nystatyn (nystatyny A2) została ustalona na podstawie analizy estru metylowego N-acetylonystatyny A2 przy pomocy metod spektroskopowych UV, MS i NMR. Widmo UV wskazało obecność w badanym związku chromoforu tetraenowego. Ciężar cząsteczkowy ustalono jako 909 j.m. na postawie analizy MS z wykorzystaniem techniki FAB, co pozwoliło wydedukować skład elementarny nystatyny A2 jako C47H75NO16. Analizy...
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Synthesis, Antimicrobial and Mutagenic Activity of a New Class of d-Xylopyranosides
PublicationEight N-[2-(2′,3′,4′-tri-O-acetyl-α/β-d-xylopyranosyloxy)ethyl]ammonium bromides, a new class of d-xylopyranosides containing a quaternary ammonium aglycone, were obtained. Their complete structure was confirmed using NMR spectroscopy (1H, 13C, COSY and HSQC) and high-resolution mass spectrometry (HRMS). An antimicrobial activity against fungi (Candida albicans, Candida glabrata) and bacteria (Staphylococcus aureus, Escherichia...
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Badanie NMR oligo(alkileno-estro-etero)dioli - monomerów do syntezy elastomerów uretanowych
PublicationCelem pracy było ustalenie rozkładu merów w zsyntezowanych oligo(alkileno-estro-etero)diolach. Ich budowę scharakteryzowano na podstawie danych z analizy widm ^1H NMR, których interpretacji dokonano wykorzystując widma COSY. Z wartości integracji odpowiednich sygnałów ustalono średnią długość cząsteczki polimeru i stopień przereagowania substratów reakcji. Bardziej szczegółowe informacje o strukturze, w tym o rozkładzie różnych...
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The structure of levorin A3, a minor component of levorin complex
PublicationBudowa chemiczna składnika kompleksu leworyn, leworyny A3, została ustalona na podstawie analizy z wykorzystaniem metod spektroskopowych UV, MS i NMR metoksykarbonylometyloamido pochodnej leworyny A3. Widmo UV wskazało obecność chromoforu heptaenowego. Ciężar cząsteczkowy leworyny A3 ustalono jako 1110 j.m. za pomocą spektrometrii masowej z wykorzystaniem techniki FAB, co po uwzględnieniu uwarunkowań biogenetycznych pozwoliło wydedukować...
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Novel, Fully Biobased Semicrystalline Polyamides
PublicationNovel, semicrystalline polyamides and co(polyamides) were synthesized from biobased sebacic acid (SA), 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroiditol (diaminoisoidide, DAII) as well as from 1,4-diaminobutane (DAB), also known as putrescine in nature. Low molecular weight polyamides were obtained by melt polycondensation of the salts based on these monomers or by interfacial polycondensation. In order to increase their molecular...
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Structure and Molecular Dynamics in Renewable Polyamides from Dideoxy-Diamino Isohexide
PublicationThe chemical structure, the conformation, andthe flexibility of the polymer chain fragments present in thepolyamides synthesized from 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol, 1,4-diaminobutane, and either sebacic orbrassylic acid have been studied by liquid-state 2D NMRspectroscopy viz. correlation spectra (COSY) and heteronuclearmultiple-bond correlation spectra (gHMBC), by 13Ccross-polarization/magic-angle spinning...
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Waterborne polyesters partially based on renewable resources
PublicationA new experimental approach for preparing biobased, water-soluble polyesters via titanium(IV) n-butoxide-catalyzed bulk polycondensation is presented. In the described method polymers were obtained from isosorbide, maleic anhydride and poly(ethylene glycol). The chemical structure of the synthesized polyesters was confirmed using 2D NMR spectroscopy and by titration methods. Careful analysis of 2D NMR spectra viz. Correlation Spectra...
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Fully Isohexide-Based Polyesters: Synthesis, Characterization, and Structure-Properties Relations
PublicationHere we present a novel series of biobasedpolyesters solely based on renewable isohexide building blocks,synthesized via melt polymerization. The recently developedisoidide dicarboxylic acid (IIDCA) was polymerized with rigidrenewable diols such as isosorbide (IS), isomannide (IM),isoidide (II), and the novel 2,5-methylene-extended isoididedimethanol (IIDML). Both IIDCA and IIDML weredeveloped to increase the reactivity of the...
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New Materiality-towards ‘Media Environments
PublicationArticle presents media solutions providing new materiality of architectural spaces. Media solutions in architecture evolve in new forms. Articlepresentsboth the developmentof new technological solutionsas well as new ways of application of media solutions in relation toarchitectural form. The aim of the article is to show technical aspects of new materiality - intelligent materials, allowing transmission of changeable visual content...